A Killian-Jaimeson Diverticulum Masquerading as a Thyroid Nodule

Background: A Killian-Jaimeson diverticulum is a rare outpouching in the cervical esophagus, just below the cricopharyngeus muscle, that can be easily mistaken for a thyroid nodule on ultrasonography (1). Clinical Case: A 65-year-old woman underwent a thyroid ultrasound after her primary care physician noted left-sided thyromegaly. The ultrasound described a 33 mm solid, hypoechoic, wider-than-tall nodule in the left mid gland with an obscured posterior margin as well as macro- and microcalcifications. Given the size and highly suspicious features on ultrasound, she was referred to endocrinology clinic for a fine needle aspiration (FNA). She underwent ultrasound-guided FNA of what appeared to be the previously described thyroid nodule. Surprisingly, the pathology report noted degenerative changes with amorphous debris and possible foreign materials (vegetable or food) without any thyroid tissue. She was sent for an MRI neck, which showed the left neck mass communicating with the esophagus, favoring a left lateral projecting Killian-Jamieson esophageal diverticulum with internal debris. She was referred to head and neck surgery. Given only minimal symptoms of dysphagia, there are no current plans for surgery. Conclusion: This case illustrates the possibility of mistaking a Killian-Jaimeson diverticulum as a thyroid nodule. Recognition of this rare disease process in the differential diagnosis of thyroid nodules with high risk ultrasound characteristics may prompt more advanced imaging with MRI or CT, and lead to an accurate diagnosis prior to subjecting patients to unnecessary and potentially harmful FNAs (2). References: (1) Kim HK, Lee JI, Jang HW, et al. Characteristics of Killian-Jamieson diverticula mimicking a thyroid nodule. Head Neck. 2012;34(4):599-603. doi:10.1002/hed.21575. (2) Bonacchi G, Seghieri M, Becciolini M. Killian-Jamieson diverticulum: real-time sonographic findings. J Ultrasound. 2016;19(4):295-298. Published 2016 Apr 21. doi:10.1007/s40477-016-0208-3.